Recently, there has been a growing interest and demand for health and relaxation. Home bathtub products equipped with jet bath functionality are widely on the market. Jet bath products are mainly intended to provide the bather with massage, fatigue recovery, and healing by water jets.
For instance, Patent Document 1 discloses a technique for generating a unidirectionally flowing uniform flow which directly and continuously impinges on the bather. The bather's body surface is stimulated by the uniform flow impinging on the bather allowed to fall in a state of complete relaxation.
For instance, Patent Document 2 describes, instead of a uniform flow, use of a water circulator pump with variable rotation speed to control the jetting amount and jetting pressure of flowing water.
For partial massage, Patent Document 3 discloses a circulation type bathtub including a footrest inside the bathtub and a jetting port for squirting a jet flow at this footrest.
On the other hand, there are proposals for providing exercise in the bathtub. Patent Document 4 discloses a technique for providing a depressible pedal in the bathtub. The pedal is provided with depression load by a spring. The bather can exercise by depressing the pedal with one foot while keeping a sitting posture.
Patent Document 5 discloses a bubble generating device in which squirt and stop of a jet flow from a jet nozzle are controlled by a controller. According to Patent Document 5, the bathing water is simultaneously squirted from two squirting positions during a certain overlap time. This allows smooth shift from one squirting position to another, and the bather feels no discomfort by the shift. However, like the circulation type bathtub disclosed in Patent Document 2, this bubble generating device is not a device which causes the bather to exercise.